The United States will withdraw nearly a third of its troops from Iraq, a top commander confirmed on Wednesday, with the move expected to happen within weeks.
The move will reduce the amount of troops from 5,200 to 3,000.
The news comes after Donald Trump said he planned to pull all troops out of Iraq as soon as possible as part of an effort to fulfill his 2016 campaign promises ahead of the November presidential election.
During a visit to Iraq, the commander of US Central Command said the reduction reflects US confidence in the ability of US-trained Iraqi security forces to handle the militant threat from the Islamic State group, which entered Iraq from Syria in 2014.
Late Tuesday, a senior Trump administration official, speaking on condition of anonymity, told reporters aboard Air Force One that such an announcement was coming and that an announcement on the withdrawal of additional troops from Afghanistan also could be expected in the coming days.
Mr Trump has been trying to make the case that he has fulfilled the promises he made four years ago as he campaigns for a second term, with one of those being his vow to end America's long-running involvement in global military conflicts.
US forces have been in Afghanistan since 2001. They invaded Iraq in 2003 and left in 2011 but returned in 2014 after the Islamic State group overran large parts of Iraq.
"In recognition of the great progress the Iraqi forces have made and in consultation and coordination with the government of Iraq and our coalition partners, the United States has decided to reduce our troop presence in Iraq from about 5,200 to 3,000 troops during the month of September", Mr McKenzie said, according to an excerpt of his remarks provided by his office.
Mr McKenzie said the remaining US troops would continue advising and assisting Iraqi security forces as they attempt to root out remnants of the Islamic State group, sometimes called ISIS.
"The US decision is a clear demonstration of our continued commitment to the ultimate goal, which is an Iraqi security force that is capable of preventing an ISIS resurgence and of securing Iraq's sovereignty without external assistance," Mr McKenzie said. "The journey has been difficult, the sacrifice has been great, but the progress has been significant."
Tensions spiked between the US and Iraq in January after a US drone strike near the Baghdad airport killed Iranian General Qassem Soleimani and Iraqi militia leader Abu Mahdi al-Muhandis. Angry Iraqi lawmakers, spurred on by Shiite political factions, passed a nonbinding resolution to oust all US-led coalition forces from the country.
In response to the Soleimani killing, Iran on 8 January launched a ballistic missile attack on al-Asad air base in Iraq, which resulted in traumatic brain injuries to more than 100 American troops. Two months later, US fighter jets struck five sites in retaliation, targeting Iranian-backed Shiite militia members believed responsible for the January rocket attack.
The Associated Press contributed to this report